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A297578
Number of nX4 0..1 arrays with every 1 horizontally, diagonally or antidiagonally adjacent to 1 or 4 neighboring 1s.
1
4, 17, 72, 254, 1104, 4428, 17549, 71541, 288624, 1160216, 4688893, 18915890, 76255262, 307700021, 1241251737, 5006436549, 20196297041, 81469428031, 328628315656, 1325648873979, 5347476219467, 21570824670637, 87013568475744
OFFSET
1,1
COMMENTS
Column 4 of A297582.
LINKS
FORMULA
Empirical: a(n) = a(n-1) +6*a(n-2) +24*a(n-3) +14*a(n-4) -26*a(n-5) -40*a(n-6) -35*a(n-7) +23*a(n-8) +48*a(n-9) -5*a(n-10) -7*a(n-11) -a(n-12) -2*a(n-14) -a(n-15) +a(n-16)
EXAMPLE
Some solutions for n=7
..0..0..0..0. .0..0..0..1. .0..1..1..1. .0..1..0..0. .0..0..0..1
..0..0..0..0. .0..1..1..1. .0..1..0..1. .1..0..0..1. .0..1..1..0
..1..1..0..0. .0..0..0..1. .0..0..0..0. .0..0..1..0. .0..1..0..1
..0..0..0..1. .0..0..0..0. .0..1..0..0. .1..0..0..0. .0..0..0..0
..0..1..1..1. .0..0..1..0. .1..0..0..0. .0..1..0..0. .0..1..0..1
..0..1..0..0. .1..1..1..0. .1..0..1..0. .0..0..0..1. .0..1..1..1
..0..0..0..0. .1..0..0..0. .1..1..1..0. .0..0..1..0. .0..0..0..0
CROSSREFS
Cf. A297582.
Sequence in context: A364705 A179606 A108929 * A022031 A255117 A001076
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 01 2018
STATUS
approved